Evaluation Of 24 V Digital Signals - Siemens SITRANS DA400 Operating Instructions Manual

Evaluating and processing signals
7.2 Evaluation of universal inputs
Figure 7-2 Universal input function diagram
See also
Parameter table (Page 6-7)
7.2.3

Evaluation of 24 V digital signals

Relates to following parameters
Parameter no.
P.26 to P.29
Evaluation
The electrical (voltage) signal is converted into a current by a multiplier and measured (see
Evaluation of analog current signals
Low or High level for the signal. The threshold value is set up so that a closing contact also
generates a High signal via the 8.2 V source. With the parameter setting ¬24V, the digital
signal is inverted.
7-4
Parameter name Adjustment/display
range
"INP1" to "INP4" "24V" and
"¬24V"
). A comparator then uses this value to determine the
Comment
24 V-Digital signal >7 V -> High
¬24 V-Digital signal <4,5 V -> High
SITRANS DA400 with protection against explosion
Operating Instructions, 02/2006, A5E00684661-01